Electric and hybrid vehicles have recently become a more common sight on roads worldwide. They have one thing in common and that is they all require a large and powerful rechargeable energy storage, also known as a battery. In most such batteries, several battery cells are stacked together to form a battery powerful enough to provide energy for the vehicle to drive for example several tens of kilometers. The battery cells are in most cases mechanically fixed together with a common frame or enclosure to form a single unit which is conveniently mounted in the vehicle. Furthermore, the size of a battery providing sufficient power for driving an electric or hybrid vehicle is relatively large, whereby the battery cells tend to be closely packed in order to reduce the size of the battery.
The high powers of the batteries constitute a high risk, in particular for passengers of the vehicle carrying the battery but also for the vehicle itself which may be damaged by a faulty battery. For example, in case of an accident causing an impact on the battery, a short circuit may occur which may result in a fire. Another example is that an impact caused by e.g. a rock may damage the battery in an unknown way. For example, the rock (or another object) may hit the battery from below the vehicle.
One example of an apparatus with an electronic sensor for detecting external physical impact is disclosed in US20060250262.
However, it is desirable to be able to more accurately assess the damage caused by an external impact in order to better determine what actions need to be taken depending on the damage.
Therefore, there is a need for improved system for damage detection in batteries for electric and hybrid vehicles.